The production of a spiro[cyclopentane]-quinolinedione is described in Chem. Pharm. Bull., 17, 1290 (1969). Several additional spiroquinoline diones are disclosed in Bull. Soc. Chim. Fr., 364 (1968). The references do not describe pharmaceutical uses for these compounds.
The compounds used in the method of this invention are disclosed in European published application No. 84 11 4974 published Jun. 19, 1985. No use for the treatment of hyperproliferative skin disease is disclosed therein.